scholarly journals Volatile Oils ofNepeta tenuifolia(Jing Jie) as an Alternative Medicine against Multidrug-Resistant Pathogenic Microbes

Author(s):  
Yi-Hsuan Lee ◽  
Chao-Min Wang ◽  
Po-Yu Liu ◽  
Ching-Chang Cheng ◽  
Zong-Yen Wu ◽  
...  

Essential oils from the dried spikes ofNepeta tenuifolia(Benth) are obtained by steam distillation. Pulegone was identified as the main component in the spikes ofN. tenuifoliathrough analysis, with greater than 85% purity obtained in this study. The essential oils are extremely active against all Gram-positive and some Gram-negative reference bacteria, particularlySalmonella enterica,Citrobacter freundii, andEscherichia coli. The minimum inhibitory concentration was found to be between 0.08 and 0.78% (againstS. enterica), 0.39 and 0.78% (againstC. freundii), and 0.097 and 0.39% (againstE. coli), whereas the minimum bactericidal concentration varied in range from 0.097% to 1.04%. In general, the essential oils show a strong inhibitory action against all tested reference strains and clinical isolates. However, the antibacterial activity of EOs against bothPseudomonas aeruginosareference strains and clinical isolates was relatively lower than other Gram-negative pathogens. The essential oils ofN. tenuifoliaalso displayed bactericidal activities (MBC/MIC < 4) in this study. These findings reflect the bactericidal activity of the essential oils against a wide range of multidrug-resistant clinical pathogens in an in vitro study. In addition, we propose the fragmentation pathways of pulegone and its derivatives by LC-ESI-MS/MS in this study.

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S319-S319
Author(s):  
Andrew Walkty ◽  
Heather Adam ◽  
Melanie Baxter ◽  
Philippe Lagace-Wiens ◽  
James Karlowsky ◽  
...  

Abstract Background Plazomicin (PLZ) is a next-generation aminoglycoside currently approved by the US FDA for the treatment of complicated urinary tract infections, including pyelonephritis. The purpose of this study was to evaluate the in vitro activity of PLZ against a large collection of Gram-negative bacilli obtained from patients attending Canadian hospitals. Methods Annually from 2011 to 2018, sentinel hospitals across Canada submitted blood, respiratory, urine, and wound isolates from patients attending ERs, medical and surgical wards, hospital clinics, and ICUs (CANWARD). Susceptibility testing was performed using broth microdilution (and breakpoints) as described by CLSI (FDA breakpoints used for PLZ). Results See table. S, susceptible; NS, nonsusceptible; ESBL, extended-spectrum β-lactamase; MDR, multidrug-resistant (NS to antimicrobials from three or more classes); n.d., not defined. Conclusion PLZ demonstrated excellent in vitro activity vs. E. coli and K. pneumoniae clinical isolates, including aminoglycoside NS, ESBL-positive, and MDR subsets. Disclosures All authors: No reported disclosures.


2020 ◽  
Author(s):  
Delaney Burnard ◽  
Gemma Robertson ◽  
Andrew Henderson ◽  
Caitlin Falconer ◽  
Michelle Bauer-Leo ◽  
...  

AbstractCefiderocol is a novel cephalosporin designed to treat multidrug resistant Gram-negative infections. By forming a chelated complex with ferric iron, cefiderocol is transported into the periplasmic space via bacterial iron transport systems and primarily binds to penicillin-binding protein 3 (PBP3) to inhibit peptidoglycan synthesis. This mode of action results in cefiderocol having greater in vitro activity against many Gram-negative bacilli than currently used carbapenems, β-lactam/β-lactamase inhibitor combinations, and cephalosporins. Thus, we investigated the in vitro activity of cefiderocol (S-649266) against a total of 271 clinical isolates of Burkholderia pseudomallei from Australia. The collection was comprised of primary isolates (92.3%) and subsequent isolates (7.7%). Minimum inhibitory concentrations (MIC) of cefiderocol ranged from ≤0.03 to 32 mg/L, where the MIC90 was 1 mg/L and 16 mg/L for primary and subsequent isolates, respectively. Based upon non-species specific (Gram-negative bacilli) clinical breakpoints for cefiderocol (MIC ≤ 4 mg/L), twelve isolates (4.4%) would be classified as non-susceptible. Further testing for co-resistance to meropenem, ceftazidime, trimethoprim-sulfamethoxazole, amoxicillin-clavulanate and doxycycline was performed on a subset of isolates with elevated cefiderocol MICs (≥2 mg/L, 4.8%) and 84.6% of these isolates exhibited resistance to at least one of these antimicrobials. Cefiderocol was found to be highly active in vitro against B. pseudomallei primary clinical isolates. This novel compound shows great potential for the treatment of melioidosis in endemic countries and should be explored further.


2017 ◽  
Vol 61 (6) ◽  
Author(s):  
Nylev Vargas-Cruz ◽  
Ruth A. Reitzel ◽  
Joel Rosenblatt ◽  
Mohamed Jamal ◽  
Ariel D. Szvalb ◽  
...  

ABSTRACT Percutaneous nephrostomy (PCN) catheters are the primary method for draining ureters obstructed by malignancy and preventing a decline of renal function. However, PCN catheter-related infections, such as pyelonephritis and urosepsis, remain a significant concern. Currently, no antimicrobial PCN catheters are available for preventing infection complications. Vascular catheters impregnated with minocycline-rifampin (M/R) and M/R with chlorhexidine coating (M/R plus CHD) have previously demonstrated antimicrobial activity. Therefore, in this study, we examined whether these combinations could be applied to PCN catheters and effectively inhibit biofilm formation by common uropathogens. An in vitro biofilm colonization model was used to assess the antimicrobial efficacy of M/R and M/R-plus-CHD PCN catheters against nine common multidrug-resistant Gram-positive and Gram-negative uropathogens as well as Candida glabrata and Candida albicans. Experimental catheters were also assessed for durability of antimicrobial activity for up 3 weeks. PCN catheters coated with M/R plus CHD completely inhibited biofilm formation for up to 3 weeks for all the organisms tested. The reduction in colonization compared to uncoated PCN catheters was significant for all Gram-positive, Gram-negative, and fungal organisms (P < 0.05). M/R-plus-CHD PCN catheters also produced significant reductions in biofilm colonization relative to M/R PCN catheters for Enterobacter spp., Escherichia coli, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, C. glabrata, and C. albicans (P < 0.05). M/R-plus-CHD PCN catheters proved to be highly efficacious in preventing biofilm colonization when exposed to multidrug-resistant pathogens common in PCN catheter-associated pyelonephritis. M/R-plus-CHD PCN catheters warrant evaluation in a clinical setting to assess their ability to prevent clinically relevant nephrostomy infections.


2016 ◽  
Vol 5 (3) ◽  
pp. 212 ◽  
Author(s):  
Hercules Sakkas ◽  
Panagiota Gousia ◽  
Vangelis Economou ◽  
Vassilios Sakkas ◽  
Stefanos Petsios ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Eshetu Gadisa ◽  
Hydar Usman

Background. Emerging of multidrug-resistant bacteria can compromise the effectiveness of antibiotics used to treat skin infections. Those bacteria imposed public health problems and questioning medical care in the 21st century. In this circumstance, essential oils of medicinal plants origin are supreme sources of structural and functionally divergent compounds, which inhibited the growth of common wound colonizing MRSA and ESBL producing P. aeruginosa. The aim of this study was to evaluate the combined antibacterial activity of essential oils extracted from Rumex abyssinicus, Cucumis pustulatus, and Discopodium penninervium against multidrug-resistant (MDR) isolates of skin ulcers. Methods. Essential oils (EOs) were extracted from aerial parts of R. abyssinicus, C. pustulatus, and D. penninervium with steam distillation. A mixture of each oil (1 : 1) was adsorbed to a disc and placed on Mueller Hinton Agar. Then, minimum zone of inhibition and bactericidal concentration of EOs was measured after incubeted for 18–24 hours at 37 °C. Their combined antibacterial effect was determined by the fractional inhibitory concentration index. Results. The antibacterial activity of mixed oil varied in their doses and bacteria species, of which a mixture of essential oil of R. abyssinicus and D. penninervium had inhibition zone (32 mm); its MIC and MBC values range from 1-2 μl/ml against MRSA. It had an inhibition zone (36 mm), MIC value 4 μl/ml, and MBC (8 μl/ml) against ESBL producing P. aeruginosa, whereas combined effects of R. abyssinicus and C. pustulatus had MIC values ranging from 2–8 μl/ml for E. coli and K. pneumoniae and 2 μl/ml for MRSA. There was a strong synergistic effect between R. abyssinicus and D. penninervium and promising antibacterial effect more specifically on MRSA and P. aeruginosa. Conclusion. This in vitro study of the combined effect of EOs has significant antibacterial activity on wound colonizing bacteria and reduces delaying wound healing as that of modern drugs tested in parallel. Hence, further structural elucidation of active compounds helps us to properly design or synthesis of topical antibiotics for wound care.


Author(s):  
Ying Zhang ◽  
Yishuai Lin ◽  
Xiaodong Zhang ◽  
Liqiong Chen ◽  
Chunyan Xu ◽  
...  

Colistin is among the few antibiotics effective against multidrug-resistant Gram-negative bacteria (GNB) clinical isolates. However, colistin-resistant GNB strains have emerged in recent years.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S581-S581
Author(s):  
Lina M Rivas ◽  
Jose R W Martínez ◽  
Maria Spencer ◽  
Lorena Porte ◽  
Francisco Silva ◽  
...  

Abstract Background The widespread dissemination of carbapenem-resistant (CR) P. aeruginosa and Enterobacteriaceae has created a major global public health crisis. C/T is a recently approved therapeutic which consists of the combination of a novel cephalosporin (ceftolozane) and tazobactam (a β-lactamase inhibitor). C/T has shown good activity against a wide range of multidrug-resistant (MDR) Gram negatives, being particularly interesting as an alternative for MDR P. aeruginosa. We aimed to determine the activity of C/T against clinical strains of Enterobacteriaceae and P. aeruginosa recovered in 4 large clinical centers from Chile. Methods We analyzed 434 isolates of Enterobacteriaceae (347 E. coli, 66 K. pneumoniae, 21 Enterobacter cloacae complex) and 57 P. aeruginosa collected during 2017 from 4 tertiary care institutions in Santiago, Chile. Identification was performed as per each local clinical microbiology lab. Susceptibility testing was performed by broth microdilution using customized Sensititre plates (Trek). Carba-NP was performed to screen for carbapenemase production. Susceptibilities were analyzed as per 2019 CLSI breakpoints. Results The MIC50/90 for C/T against Enterobacteriaceae and P. aeruginosa were 1/4 μg/mL and 2/16 μg/mL, respectively. In Enterobacteriaceae, susceptibility to C/T reached 92% in E. coli (Figure 1A), 91% in E. cloacae complex (Figure 1B) and 70% in K. pneumoniae (Figure 1C). Remarkably, C/T remained active against 58% (33/57) of CR Enterobacteriaceae (Figure 2A). Among Carba-NP-negative CR isolates (46%, 26/57), susceptibility to C/T was 54% (Figure 3 A–C). In P. aeruginosa, the overall susceptibility to C/T was 81% (Figure 1D), maintaining activity against 69% (25/36) of CR strains (Figure 2B). Importantly, susceptibility to C/T in CR P. aeruginosa isolates with a negative Carba-NP (67%, 24/36) was 83% (20/24) (Figure 3D). Conclusion In this multicenter study, we observed that C/T was highly active against clinical isolates of Enterobacteriaceae and P. aeruginosa. Of note, C/T remained active against a large proportion of CR clinical strains. Moreover, the activity of C/T was particularly high against CR P. aeruginosa isolates with a negative Carba-NP. Disclosures All authors: No reported disclosures.


Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2575 ◽  
Author(s):  
Medbouhi ◽  
Benbelaïd ◽  
Djabou ◽  
Beaufay ◽  
Bendahou ◽  
...  

The chemical composition of essential oils extracted from aerial parts of Eryngium campestre collected in 37 localities from Western Algeria was characterized using GC-FID and GC/MS analyses. Altogether, 52 components, which accounted for 70.1 to 86.8% of the total composition oils were identified. The main compounds were Germacrene D (0.4–53.4%), Campestrolide (1.6–35.3%), Germacrene B (0.2–21.5%), Myrcene (0.1–8.4%), α-Cadinol (0.2–7.6%), Spathulenol (0.1–7.6%), Eudesma-4(15)-7-dien-1-β-ol (0.1–7.6%) and τ-Cadinol (0.3–5.5%). The chemical compositions of essential oils obtained from separate organs and during the complete vegetative cycle of the plant were also studied. With the uncommon 17-membered ring lactone named Campestrolide as the main component, Algerian E. campestre essential oils exhibited a remarkable chemical composition. A study of the chemical variability using statistical analysis allowed the discrimination of two main clusters according to the geographical position of samples. The study contributes to the better understanding of the relationship between the plant and its environment. Moreover, the antimicrobial activity of the essential oil was assessed against twelve strains bacteria and two yeasts involved in foodborne and nosocomial infections using paper disc diffusion and dilution agar assays. The in vitro study demonstrated a strong activity against Gram-positive strains such as S. aureus, B. cereus, and E. faecalis. The cytotoxicity and antiparasitic activities (on Lmm and Tbb) of the collective essential oil and one sample rich in campestrolide, as well as some enriched fractions or fractions containing other terpenic compounds, were also analyzed. Campestrolide seems to be one compound responsible for the cytotoxic and antileishmanial effect, while myrcene or/and trans-β-farnesene have a more selective antitrypanosomal activity.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S326-S326
Author(s):  
Alejandro Iregui ◽  
Zeb Khan ◽  
David Landman ◽  
John M Quale

Abstract Background Antibiotic-resistant Gram-negative bacteria, including KPC-producing Enterobacteriaceae and carbapenem-resistant A. baumannii, have been problematic hospital pathogens in NYC and other areas. Eravacycline (ERV), a fluorocycline antibiotic released in the USA in 2018, has demonstrated in vitro activity against many of these strains. We tested the activity of ERV against a recent collection of clinical isolates from NYC hospitals. Methods For a 3-month period in 2017, all unique patient isolates of E. coli, K. pneumoniae, Enterobacter spp., and A. baumannii were collected from 7 hospitals in Brooklyn, NY. MICs were performed by broth microdilution for ERV and Tigecycline (TGC) and agar dilution for other antibiotics according to CLSI methodology. Cephalosporin-resistant isolates were screened by PCR for common carbapenemases. Results The susceptibility results for tetracycline and ERV are listed in the Table. Overall, 95% of the Enterobacteriaceae were inhibited by ≤ 0.5 μg/mL of ERV, the FDA-suggested breakpoint. Of 1,876 isolates of E. coli, 4 possessed KPC. ERV MICs for these 4 isolates were 0.125–0.25 μg/mL. Of 518 isolates of K. pneumoniae, 20 possessed KPC. The ERV MIC50 and MIC90 for these isolates were 1 and 1 μg/mL, respectively. Of 172 isolates of Enterobacter spp., 3 possessed KPC. ERV MICs for these 3 isolates were 0.5–1 μg/mL. Of 45 isolates of A. baumannii, 11 isolates possessed a carbapenemase (OXA23 in 8, OXA24 in 2, and KPC in 1). The ERV MIC50 and MIC90 for these isolates were 1 and 2 μg/mL, respectively. Overall, ERV MICs were two-fold lower than TGC MICs for A. baumannii. Conclusion ERV possesses significant in vitro activity against contemporary clinical isolates of Enterobacteriaceae and A. baumannii from NYC, including many carbapenemase producing strains. Disclosures All authors: No reported disclosures.


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